Clutch



1` `Nov.12,1940. n HQGEYER f 2,221,399`

CLUTCH Filed Feb.` 9, 1938 2 Sheets-Sheet l linventor e Patented Nov. 12,1940

CLUTCH Harvey D. Geyer, Dayton, (lhio, assgnor to Gen-` l eral Motors tlorporaton,` Detroit, Michi, acor-p` poration Aof Delaware v e Application February 9. 1933, seriaiNv. 189,483

` caninas.` (01492-32), f

t This invention relatesto friction clutchesiand `has been designed `more particularly to improve theclutch for coupling the engine shaft and transmission shaftof a" motor vehicle.` i e An object of the `invention is to add a selfenergizing mechanisrnto assist the spring used in the conventional way toeilect clutch engage-` ment to couple the shafts.

Asca further 'object the inventibnmakes it possible` to use a lighter clutch engaging spring.

Beinglighterl the spring may` therefore` be less expensive.k Y e e A further and related;` object is the provision of a clutch so constructed as to reduce the pedal 1li` pressure required :for clutch release. i

Other objects and advantages Will be understood fromgthe following description(` On the accompanying drawings: f Figure 1 is a view of the clutch in elevation.

`zo Figure 2 is a seencnon` nuez- 2 `ofrigure 1.`

` `Figure3 is a lpartial section corresponding to e Figure 2, but showing` the parts displacedfrom theposition they occupy inFig-ur 2. Y

`Figure 4 is a section on line 4-4 of Figure 2.

"25. Numeral`1 represents thelengine shaft and 9 the transmission shaft. The latter is piloted into "the end of the former, `an anti-friction bearing being provided at Il. `Fastening means I3 sef curesto` the engine shafta fiywheelfli. Secured to the flywheel -byY fastening meansH is a cover l I9 which also serves the purpose of a spring abutment. Within: the cover is a pressure plate 2l mounted centrally relatively to the cover, suit- A able means 23 being` provided to effect the cen- II traliz'ation. This means permits axial sliding ol.' i

` the pressure platerelative to the cover.

`The driven shaft 9 is provided with a hub 25 e 4to which is secured a driven plate 21 with fac- `ings 29. `Springsiil provide a yielding resist- 4p ance to a relative circumferential movement between the hub 25 and the plate 21.

A circular series of shouldered fulcr-um pins A23 is carried by` the cover plate. These pins have heads and they support two` rings31 and 39.

A clutchspring in the form of a coned ll pressure plate. Inwardly from the circle of Iulblock from .thev cover plate.

crum pins` the spring plate isfslotted toform tongues 45. The tongues are collectivelyrsecured yto a throwout collar 41 by suitable means designated as a wholeby numeral 49. 'The collar is reciprocated by a throwoutlever, only the 5 forked ends 5I` of which are shown. ft

A plurality of steel inserts 53 are distributed in a circular series yabout and `carried by the pressureplate.` Each insert is formed with a` somewhat conical but `radially elongated notch 10 55.1` Opposite each insert is a`block'51 secured tothe cover, the `block axially spaced from the insert 53.A The block, too, has a conicalnotch `59. To secure the `block in position there are used shouldered studs 6I serving to` `space the 15 The parts are secured in position by nuts 63 and machine screws `65.1 These fastening means are located Within rectangular part of `the lever `is provided with slots 1I. fIhe parts 13 of the lever between "each slot andthe adjacent edge is bent slightlyso` 8D that `its `pressure against theblock 51 tends torock the lever rclockwise and force the rectangular` plate portion of the lever to the position shown in Figure `2, the ballrnoving radially tward the center `of `the clutch and into the more 85 shallow parts of the opposed notches. When the ball is `thus 'forced into the shallow parts of the notchesit will be evident that the pressure plate 2l is forced toward the driven plate. This movement provides a y self-energizing action which 40 serves to supplement the action of the main clutch spring 4I. As a result it makes possible `the use of a lighter and therefore less expensive main spring. `Since theI spring is lighter, less pedal eiort is required to overcome the spring action in the act of clutch release.

The leverhas arms 15 which extend axially through adjacent slots of the spring and these arms are pivoted on a cotter pin 11 orS-the like which is .carried by a bracket 19, the latter riveted or otherwise secured as at 8l to a flange 83 of the cover. The extreme inner end of the lever as at 85 is positioned to be free from contact with the main spring whenv the clutch is engaged. When however, the spring 4| is moved 55 PATENT oFFlcE leased to permit spring 4I to effect clutch engagement, the resilienttongues 13 ofthe lever 69 again rock the leverto'the position shown by Figure 2 and the ball moves into the shallower parts of the notches and the self-energizing action assists the spring.

It may be further explained that the torque is transmitted between the cover I 9 and the pressure plate 2| not by lugs and slots 4as is common practice. When the clutch begins to engage vthere is a slight relative circumferential movement between parts I9 and 2| nconsequence of the drag of the pressure plate as it contacts the driven plate. The resultant relative circumferential movement is shown by Figure 4. The slot in lever 69 is provided to accomodate the movement of the ball during such Yrelative movement of parts -I9 and 2|. The motion is quite limited Yas the ball engages thefaces of parts 53 and 51 `and ,quickly stops such rotation.

Thereafter parts I9 and 2| move jointly and torque is transmitted from the one to the other through the ball.` After the lever 69 isrendered free to rotate as the clutch engages the ball' is forced radially into narrower parts of the notches as is shownby Figure 2 to thereby supplement the action of the main spring. When the throwout mechanism overcomes the mainspring it operates upon lever 69 to restore the ball 61 by an opposite radial movement and, since the pressure plate is jno longer forced against the drivenA platethe ball returns to its intermediate position circumferentially;

I claim:

l1. In a clutch, the rst member comprising a rotatable element, a cover secured thereto and a pressure plate within said cover and rotatable slightly relatively to said cover and also movable axially relative thereto, a second member adapted to be gripped between said rotatable ,element plate, a plurality of. levers pivoted to said cover,

each lever having one arm extending between saidinsert and block, said arm having an aperture embracing said ball, said lever having a second arm in the path of movement of said spring p as it moves to clutch releasing position, said lever having resilient parts tobias said ball toward the shallowparts of said recesses.

2. Thev invention defined by claim 1,V said re-` silient parts being formed as tongues bent from the plate of the leverarm and between an insert and block to engage the .blockv and thereby rock the lever about its pivot axis.

3. In combination, a first shaft, a ywheel sesaid flywheel, a pressure plate between said ilywheel and abutment, said pressure plate being rotatable with said flywheel and reciprocable axially relative' thereto, a second shaft, a driven Vdisc carried thereby and positioned between said cured thereto, an abutment member'secured to n iiywheel and pressure plate, a coned spring an l `nulusoperable to move said pressure plate t0- `ward saidflywheel; wedgivng means between said abutment plate. and pressure plate, saidwedging means being normally operable to assist said spring annulusA and `I neans'out of contact with said spring annulus when the clutch is rengaged but adapted to be engaged by said springannulus as the latter moves to'clutch releasing position to render said Wedging means inoperative.

4. The invention defined by claimB, said Wedging means comprising elements having opposed tapering recessescarried by saidv pressure plate self-energizing devices between said` parts, each device including opposed conical recesses in said partsandv roller members in said recesses, said self-energizing devices adapted to Asupplement said spring in effecting clutch engagement, and means out of contact with said spring in its clutch engagedposition but, in the released position of the clutch, adapted to engage and be movedbysaid spring to move said rollers to the deeper parts of said conical recesses and to thereby render inoperative said self-energizing dev1ces.

Y6. The invention defined' by claim 5, said last named means being a lever pivotedto one of said parts, said lever having a resilient Vfinger yieldingly engaging one Vof said` parts.

HARVEY D. GEYER. s 

